A situation may occur where not only elderly people but also a generation that is generally unrecognized as the elderly people, for example, people in their late 40 s to 50 s unexpectedly stumble over a step, which they would not have stumbled in their early days. It is considered that this occurs because raising of a foot or an angle of a toe is insufficient, as compared with a walking state under a condition where the people do not stumble. Normally, the people are unaware of this insufficiency, and the foregoing often occurs unconsciously due to age-related weakening eyesight, deterioration of cognitive ability, muscular weakness, and the like. Moreover, an endurance capacity is also deteriorated, and thus, when the people become tired with prolonged walking, a similar phenomenon may be caused.
In Patent Document 1, there is disclosed a walking observing apparatus that detects whether or not abnormal walking occurs in an elderly person wearing the observing apparatus at his or her waist to collect data during walking of the wearer. By giving appropriate prescription to the elderly person in accordance with the collected data, measures to prevent falls or the like are taken.
In Patent Document 2, there is disclosed a fall prevention training assist apparatus including an inclination sensor mounted on a side surface of a supporter to be worn on a foot, a sound generating unit that generates sound by a signal of the inclination sensor, and a pressure sensor mounted on a lower side of a heel of the supporter. An inclination angle of a toe of the foot is sensed by the inclination sensor, and when determined that the inclination angle is insufficient as compared with that of normal walking, the wearer is notified by the sound generated by the sound generating unit to assist, for example, training to normalize walking of an elderly person.
However, the observing apparatus described in Patent Document 1 is intended to observe the walking of the elderly person to collect the data, and is not intended to prevent falls during actual walking.
Patent Document 2 describes that a person stumbles over a doorsill or the like and falls because the inclination angle of the foot is small. However, for example, when the person ascends the step or the like, not only the inclination angle of the foot but also a lifting amount of the foot or a lifting velocity give influence. Therefore, when only the inclination angle of the foot is detected, the person cannot necessarily ascend the step without stumbling. In Patent Document 2, the walker, while listening to the sound generated when the inclination angle of the foot taking a step is at a predetermined level or higher, learns how to walk so as to emit the sound. However, when the person actually almost falls, the apparatus does not sense the fall to urge the person to perform movement for fall prevention.
Patent Document 1: Japanese Unexamined Patent Publication No. H10-165395
Patent Document 2: Japanese Unexamined Patent Publication No. 2006-158431